High-molecular polypropylene with a broad distribution of the molecular weight and a short isotactic sequence length

ABSTRACT

Propylene polymers containing from 0 to 2.5% by weight of C 2 -C 10 -olefin comonomers have an M w  of from 350,000 to 1,000,000 g/mol, an M w /M n  of from 4 to 10, a proportion by weight of the polymer fraction having a viscosity number of from 500 to 1400 ml/g of from 20 to 80% of the total polymer and a proportion by weight of a polymer fraction having a viscosity number of from 200 to 400 ml/g of from 80 to 20% of the total polymer and an isotactic sequence length of from 50 to 100.

The present invention relates to propylene polymers containing from 0 to2.5% by weight of C₂-C₁₀-olefin comonomers and having an M_(w) of from350,000 to 1,000,000 g/mol, an M_(w)/M_(n) of from 4 to 10, a proportionby weight of the polymer fraction having a viscosity number of from 500to 1400 ml/g of from 20 to 80% of the total polymer and a proportion byweight of a polymer fraction having a viscosity number of from 200 to400 ml/g, of from 80 to 20% of the total polymer and an isotacticsequence length of from 50 to 100.

The present invention further relates to the use of such propylenepolymers (hereinafter referred to as “propylene polymers of the presentinvention”) for producing fibers, films and moldings, in particular forproducing tubes having a high creep rupture strength under internalpressure (creep rupture strength hereinafter referred to as “CRS”), thefibers, films and moldings, in particular the tubes having a high CRS,made from the propylene polymers of the present invention and the use ofthe moldings, in particular the tubes having a high CRS, in theconstruction of chemical apparatus, as drinking water pipe and aswastewater pipe.

High molecular weight propylene polymers can be prepared usingconventional Ziegler catalysts based on a titanium compound/an aluminumalkyl, as is described, for example, in DE-A 40 19 053. The expression“high molecular weight propylene polymers” usually refers to propylenepolymers which have a molecular weight M_(w) measured by GPC (gelpermeation chromatography) of more than about 500,000 g/mol and acorresponding melt flow rate at 230° C. under a load of 5 kg (MFR 230/5,measured in accordance with ISO 1133) of at least about 3 dg/min. Incontrast thereto, customary propylene polymers have an M_(w) of fromabout 100,000 g/mol to about 300,000 g/mol and correspondingly an MFR(230/5) of more than 4 dg/min.

The high molecular weight propylene polymers obtainable using Zieglercatalysts (hereinafter referred to as “high molecular weight Zieglerpropylene polymers”) generally have a large mean length of isotacticsequences “n-iso”, (measured using the ¹³C-NMR method as described byzambelli et al. Macromolecules 8, 687-689(1975); the value is usuallyover 100. Further properties of such high molecular weight Zieglerpropylene polymers are a comparatively high proportion of xylene-solublesubstances “XS value” (XS value determined as described in the examples)and a comparatively high melting point of generally more than 160° C.(determined by the DSC method, as described in the examples). Whenprocessed, for example by extrusion, to produce shaped articles such astubes, etc., such high molecular weight Ziegler propylene polymersdisplay poor processability (in particular poor flow) and the articlesproduced often have poor organoleptic properties (odor, taste). Theunsatisfactory organoleptic properties are caused, on the basis ofpresent-day knowledge, by low molecular weight, oily propyleneoligomers.

Attempts are usually made to circumvent the unsatisfactoryprocessability of the high molecular weight Ziegler propylene(homo)polymers by changing to high molecular weight Zieglerpropylene-olefin copolymers which have a lower melting point andtherefore flow more readily at a given temperature during extrusion thando the analogous homopolymers. However, the copolymers have an increasedcontent of readily soluble propylene oligomers, again resulting in highproportions of xylene-soluble material and unfavorable organolepticproperties of the high molecular weight Ziegler propylene copolymers.

In addition, the tubes produced from high molecular weight Zieglerpropylene polymers, for example as described in DE-A 40 19 053, havehigh brittleness (low CRS) and a rough (internal) surface. The roughsurface provides, on the basis of present-day knowledge, a large surfacearea for attack by liquids, and the liquids leach out the polymerstabilizer present in the tube, which once again reduces the CRS of thetubes.

It is an object of the present invention to find propylene polymerswhich can easily be processed (inter alia due to improved flow) by meansof conventional manufacturing tools to give shaped bodies, in particulartubes, which have not only low brittleness and a smooth surface but alsoa high toughness and good stiffness combined with a good CRS of theshaped bodies, in particular tubes.

We have found that this object is achieved by the propylene polymers ofthe present invention, the use of such propylene polymers for producingfibers, films and moldings, the fibers, films and moldings made of thepropylene polymers of the present invention and the use of the tubes inthe construction of chemical apparatus, as drinking water pipes and aswastewater pipes.

The propylene polymers of the present invention are generally obtainedby means of at least two-stage polymerization (known as the cascademethod) of propylene together with from 0 to 2.5% by weight ofC₂-C₁₀-olefin comonomers, preferably from 0 to 1.5% by weight ofC₂-C₁₀-olefin comonomers and in particular from 0 to 1% by weight ofC₂-C₁₀-olefin comonomers, in the presence of metallocene catalystsystems (as described below).

Suitable C₂-C₁₀-olefin comonomers are ethylene, 1-butene, 1-pentene,1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. It is possible tocopolymerize a plurality of comonomers or only one comonomer with thepropylene. The abovementioned % by weight are then based on the sum ofthe comonomers. Preferred C₂-C₁₀-olefin comonomers are ethylene,1-butene and 1-hexene. Preferred propylene-olefin copolymers arepropylene-ethylene copolymers, propylene-1-butene copolymers andpropylene-ethylene-1-butene terpolymers. The total amount of comonomersin these cases, too, is in the range from 0.1 to 2.5% by weight,preferably in the range from 0.1 to 1.5% by weight, in particular in therange from 0.1 to 1% by weight.

The polymerization reactions, generally at least two-stage reactions,can essentially be carried out continuously or batchwise by all suitableolefin polymerization methods. They can be carried out in the gas phase,for example in a fluidized-bed reactor or a stirred gas phase, in theliquid monomers, in solution or in suspension in suitable reactionvessels or in loop reactors. The polymerization temperature is usuallyin the range from 0 to 150° C., preferably in the range from 30 to 100°C., the pressure is in the range from 5 to 500 bar, preferably from 10to 100 bar, and the mean residence time is in the range from 0.5 hour to6 hours, preferably from 0.5 to 4 hours.

A well-suited polymerization method is the two-stage bulk polymerizationprocess.

Here, a high molecular weight propylene homopolymer or copolymer of thecomposition described above, preferably a propylene homopolymer, havinga viscosity of from 500 to 1400 ml/g (determined by the method disclosedin the examples) and a proportion of the total polymer of from 20 to 80%by weight, preferably from 45 to 75% by weight, particularly preferablyfrom 48 to 65% by weight, is prepared in the first reaction step, whilein the second, usually downstream reaction step, a low molecular weightpropylene homopolymer or copolymer of the composition described above,preferably a propylene homopolymer, having a viscosity of from 200 to400 ml/g and a proportion of from 20 to 80% by weight, preferably from25 to 55% by weight, particularly preferably from 35 to 52% by weight,is prepared.

The first and second reaction steps can be carried out batchwise orcontinuously. Preference is given to continuous operation. The firstpolymerization step is generally carried out in liquid propylene at from55 to 100° C. and a residence time of from 0.5 to 3.5 hours. A phaseratio in the range from 2.5 to 4 l of liquid propylene per kg of PP,preferably 3.3 l of liquid propylene per kg of PP, is usually set. Toregulate the molar mass, hydrogen is generally metered in.

After the first reaction step, the multiphase system is generallytransferred to the second reaction step and polymerized there at from 55to 100° C. The second reaction step generally takes place in a secondreactor. There, a phase ratio of from 1 to 2.5 l of liquid propylene perkg of PP, preferably 1.9 l of liquid propylene per kg of PP, is usuallyset.

According to the present invention, different phase ratios arepreferably set in the two reactors in the process described here.Ethylene and hydrogen are likewise metered in, as described above.

The temperatures and hydrogen concentrations in the two reactors may beidentical or different. Suitable reactors are stirred vessels or loopreactors.

It is possible to depressurize the monomer between the two reactors andto introduce the still polymerization-active catalyst/polymer systeminto the second reactor. In the second reactor, it is possible to set alower hydrogen concentration than in the first reactor.

The propylene polymers of the present invention have a mean molecularweight M, (determined by gel permeation chromatography at 135° C. in1,3,4-trichlorobenzene as solvent using a PP standard) of from 350,000g/mol to 1,000,000 g/mol, preferably from 350,000 g/mol to 800,000 g/moland in particular from 400,000 to 650,000 g/mol.

The molecular weight distribution M_(w)/M_(n) (determined by gelpermeation chromatography at 135° C. in 1,3,4-trichlorobenzene assolvent using a PP standard) of the propylene polymers of the presentinvention is in the range from 4 to 10, preferably in the range from 4to 8.

The isotactic sequence length n-iso of the propylene polymers of thepresent invention (determined as described at the outset) is in therange from 50 to 100, preferably in the range from 55 to 95 and inparticular in the range from 60 to 90.

According to the present invention, preference is given to productshaving an MFR (230/5), determined in accordance with ISO 1133, of from0.01 to 5 dg/min, particularly preferably from 0.02 to 2 dg/min.

The propylene polymers of the present invention having the compositionas described above can be fractionated by customary methods of polymerfractionation to give at least two fractions which have differentviscosities, viz. molecular weights M_(w). The high molecular weightfraction of the propylene homopolymer or copolymer, preferably propylenehomopolymer, of the present invention generally has a viscosity (=VN) offrom 500 to 1400 ml/g (determined by the method disclosed in theexamples) and a proportion of the total polymer of from 20 to 80% byweight, preferably from 45 to 75% by weight, particularly preferablyfrom 48 to 65% by weight.

The low molecular weight fraction of the propylene homopolymer orcopolymer, preferably propylene homopolymer, of the present inventiongenerally has a viscosity VN of from 200 to 400 ml/g and a proportion ofthe total polymer of from 20 to 80% by weight, preferably from 25 to 55%by weight, particularly preferably from 35 to 52% by weight.

On the basis of present-day knowledge, this narrow weight distributionspectrum of the different fractions of the propylene polymers of thepresent invention makes a large contribution to the improved properties(especially the CRS) of the fibers, films and especially moldings (e.g.tubes) which can be produced from the propylene polymers of the presentinvention.

The propylene polymer of the present invention obtained after thepolymerization reaction is usually admixed with stabilizers, lubricants,fillers, pigments, etc., and granulated.

The polymerization of the propylene, if desired together with thecomonomers described, takes place, preferably in the processesdescribed, in the presence of metallocene catalyst Systems. Themetallocene catalyst systems usually comprise a metallocene componentA), a cocatalyst (also known as activator) B) and, if desired, supportmaterials C) and/or organometallic compounds D) as scavengers.

As metallocene component A) of the metallocene catalyst system, it is inprinciple possible to use any metallocene which, under the specifiedpolymerization conditions, produces isotactic polypropylene having asufficiently high molar mass, i.e. an M_(w) of generally greater than350,000 g/mol, and a sufficiently high melting point, i.e. generallygreater than 150° C.

The metallocene can be either bridged or unbridged and have identical ordifferent ligands. Preference is given to metallocones of groups IVb ofthe Periodic Table of the Elements, namely of titanium, zirconium orhafnium.

It is of course also possible to employ mixtures of differentmetallocenes as component A).

Well-suited metallocene components A) are those described, for example,in DE-A 196 06 167, which is hereby expressly incorporated by reference.Particular mention may be made of the disclosure on page 3, line 28 topage 6, line 48 of DE-A 196 06 167.

Preferred metallocene components A) are those of the formula (I) below

where

M¹ is a metal of group IVb of the Periodic Table of the Elements,

R¹ and R² are identical or different and are each a hydrogen atom,C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₂₀-aryl group, aC₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group, an OH group, an NR¹² ₂group, where R¹² is a C₁-C₂-alkyl group or a C₆-C₁₄-aryl group, or ahalogen atom,

R³ to R⁸ and R^(3′) to R^(8′) are identical or different and are each ahydrogen atom, a C₁-C₄₀-hydrocarbon group which may be linear, cyclic orbranched, e.g. a C₁-C₁₀-alkyl group, a C₂-C₁₀-alkenyl group, aC₆-C₂₀-aryl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl group ora C₈-C₄₀-arylalkenyl group, or adjacent radicals R⁴ to R⁸ and/or R^(4′)to R^(8′) together with the atoms connecting them form a ring system,

R⁹ is a bridge, preferably

R¹⁰ and R¹¹ are identical or different and are each a hydrogen atom, ahalogen atom or a C₁-C₄₀ group such as a C₁-C₂₀-alkyl group, aC₁-C₁₀-fluoroalkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₄-aryl group, aC₆-C₁₀-fluoroaryl group, a C₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group,a C₇-C₄₀-aralkyl group, a C₇-C₄₀-alkylaryl group or a C₈-C₁₀-arylalkenylgroup or R¹⁰ and R¹¹ together with the atoms connecting them form one ormore rings and x is an integer from zero to 18,

M² is silicon, germanium or tin, and the rings A and B are identical ordifferent, saturated, unsaturated or partially saturated.

R⁹ can also link two units of the formula I with one another.

In formula I, it is particularly preferred that

M¹ is zirconium or hafnium,

R¹ and R² are identical and are methyl or chlorine, in particularchlorine, and R⁹=M²R¹⁰R¹¹, where M² is silicon or germanium and R¹⁰ andR¹¹ are each a C₁-C₂₀-hydrocarbon group such as C₁-C₁₀-alkyl orC₆-C₁₄-aryl.

The indenyl or tetrahydroindenyl ligands of the metallocones of theformula I are preferably substituted in the 2 position, 2,4 positions,4,7 positions, 2,6 positions, 2,4,6 positions, 2,5,6 positions, 2,4,5,6positions or 2,4,5,6,7 positions, in particular in the 2,4 positions.Preferred substituents are C₁-C₄-alkyl groups such as methyl, ethyl orisopropyl or C₆-C₂₀-aryl groups such as phenyl, naphthyl or mesityl. The2 position is preferably substituted by a C₁-C₄-alkyl group such asmethyl or ethyl. If the 2,4 positions are substituted, then

R⁵ and R^(5′) are preferably identical or different and are each aC₆-C₁₀-aryl group, a C₇-C₁₀-arylalkyl group, a C₇-C₄₀-alkylaryl group ora C₈-C₄₀-arylalkenyl group.

The following nomenclature is employed for the site of substitution:

Further metallocones of particular importance are those of the formula Iin which the substituents in the 4 and 5 positions of the indenylradicals (R⁵ and R⁶ or R^(5′) and R^(6′)) together with the atomsconnecting them form a ring system, preferably a six-membered ring. Thisfused-on ring system can likewise be substituted by radicals having themeanings of R³-R⁸. An example of such a compound I isdimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride.

Particular preference is given to compounds of the formula I which beara C₆-C₂₀-aryl group in the 4 position and a C₁-C₄-alkyl group in the 2position. An example of such a compound of the formula I isdimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride.

Examples of metallocone components A in the process of the presentinvention are:

dimethylsilanediylbis(indenyl)zirconium dichloride

dimethylsilanediylbis(4-naphthylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methylbenzoindenyl)zirconium dichloride

dimethylsilanediylbis(2-methylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-(p-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-t-butylindenylzirconium dichloride

dimethylsilanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-ethylindenyl)zirconium dichloride

dimethylsilanediylbis (2-methyl-4-α-acenaphthindenyl)zirconiumdichloride

dimethylsilanediylbis(2,4-dimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-thylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4,5-diisopropylindenyl)zirconiumdichloride

dimethylsilanediylbis(2,4,6-trimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2,5,6-trimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2,4,7-trimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-5-isobutylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-5-t-butylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-phenanthrylindene)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-phenanthylindenyl)zirconium dichloride

methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-(methylbenzo)indenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)-indenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4-acenaphthindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methylindenyl)zirconium dichloride

methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)zirconiumdichloride

1,2-ethanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

1,2-ethanediylbis(2-methyl-4,6-diisopropylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

1,2-ethanediylbis(2,4,7-trimethylindenyl)zirconium dichloride

1,2-thanediylbis(2-methylindenyl)zirconium dichloride

1,4-butanediylbis(2-methylindenyl)zirconium dichloride

bis(butylcyclopentadienyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

bis(methylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)Zr³⁰ CH₂CHCHCH₂B-(C₆F₅)₃

1,2-ethanediylbis(2-methylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

1,4-butanediylbis(2-methylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(2-methyl-4-phenylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)Zr⁺CH₂CH—CHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(2-methyl-4-phenylindenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediylbis(indenyl)Zr⁺CH₂CHCHCH₂B-(C₆F₅)₃

dimethylsilanediyl(tert-butylamino)(tetramethylcyclopentadienyl)zirconiumdichloride

[tris(pentafluorophenyl)(cyclopentadienylidene)borato](cyclo-pentadienyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium

dimethylsilanediyl[tris(pentafluorophenyl)(2-methyl-4-phenyl-indenylidene)borato](2-methyl-4-phenylindenyl)-1,2,3,4-tetra-phenylbuta-1,3-dienylzirconiumdimethylsilanediyl-[tris(trifluoromethyl)(2-methylbenzindenyl-iden)borato](2-methylbenzindenyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium

dimethylsilanediyl-[tris(pentafluorophethyl)(2-methyl-indenyl-iden)borato](2-methylindenyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium

dimethylsilanediylbis(indenyl)dimethylzirconium

dimethylsilanediylbisC₄-naphthylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methylbenzoindenyl)dimethylzirconium

dimethylsilanediylbis(2-methylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-t-butylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-ethylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-α-acenaphthindenyl)dimethylzirconium

dimethylsilanediylbis(2,4-dimethylindenyl)dimethylzirconium

dimethylsilanediylbis(2-ethylindenyl)dimethylzirconium

dimethylsilanediylbis(2-ethyl-4-ethylindenyl)dimethylzirconium

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4,5-diisopropylindenyl)dimethylzirconium

dimethylsilanediylbis(2,4,6-trimethylindenyl)dimethylzirconium

dimethylsilanediylbis(2,5,6-trimethylindenyl)dimethylzirconium

dimethylsilanediylbis(2,4,7-trimethylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-5-isobutylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-5-t-butylindenyl)dimethylzirconium

dimethylsilanediylbis(2-methyl-4-phenanthrylindenyl)dimethylzirconium

dimethylsilanediylbis(2-ethyl-4-phenanthrylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4,5-(methylbenzo)indenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)indenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4-α-acenaphthindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)dimethylzirconium

methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)dimethylzirconium

1,2-ethanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium

1,2-butanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium

1,2-thanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium

1,4-butanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium

1,4-butanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium

1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium

1,2-ethanediylbis(2,4,7-trimethylindenyl)dimethylzirconium

1,4-butanediylbis(2-methylindenyl)dimethylzirconium

Pariticular preference is given to:

dimethylsilanediylbis(2-methylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-(p-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-α-acenaphthindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-phenanthrylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-phenanthrylindenyl)zirconium dichloride

methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)zirconiumdichloride

Methods of preparing metallocenes of the formula I are described, forexample, in Journal of Organometallic Chem. 288 (1985) 63-67 and thedocuments cited therein.

As cocatalyst component B), the catalyst system of the present inventionusually further comprises open-chain or cyclic aluminoxane compoundsand/or other compounds B) capable of forming metallocenium ions. Thesecan be Lewis acids and/or ionic compounds having noncoordinating anions.

The aluminoxane compounds are usually described by the formula II or III

where

R²¹ is a C₁-C₄-alkyl group, preferably a methyl or ethyl group, and m isan integer from 5 to 30, preferably from 10 to 25.

The preparation of these oligomeric aluminoxane compounds is usuallycarried out by reacting a solution of trialkylaluminum with water and isdescribed, for example, in EP-A 284 708 and U.S. Pat. No. 4,794,096.

In general, the oligomeric aluminoxane compounds obtained are in theform of mixtures of both linear and cyclic chain molecules of variouslengths, so that m is to be regarded as a mean. The aluminoxanecompounds can also be present in admixture with other metal alkyls,preferably aluminum alkyls.

Further compounds which can be used as component B) arearyloxyaluminoxanes as described in U.S. Pat. No. 5,391,793,aminoaluminoxanes as described in U.S. Pat. No. 5,371,260,aminoaluminoxane hydrochlorides as described in EP-A 633 264,siloxyaluminoxanes as described in EP-A 621 279 or mixtures thereof.

As Lewis acid, preference is given to using at least one organoboron ororganoaluminum compound containing C₁-C₂₀ groups such as branched orunbranched alkyl or haloalkyl, e.g. methyl, propyl, isopropyl, isobutyl,trifluoromethyl, unsaturated groups such as aryl or haloaryl, e.g.phenyl, tolyl, benzyl, p-fluorophenyl, 3,5-difluorophenyl,pentachlorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl and3,5-di(trifluoromethyl)phenyl.

Particular preference is given to organoboron compounds.

Examples of Lewis acids are trifluoroborane, triphenylborane,tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane,tris(4-fluoromethylphenyl)borane, tris(pentafluorophenyl)borane,tris(tolyl)borane, tris(3,5-dimethylphenyl)borane,tris(3,5-dimethylfluorophenyl)borane and/ortris(3,4,5-trifluorophenyl)borane. Particular preference is given totris(pentafluorophenyl)borane.

Well-suited ionic compounds which contain a noncoordinating anion are,for example, tetrakis(pentafluorophenyl)borate, tetraphenylborate,SbF₆−, CF₃SO₃− or CIO₄−. As cationic counterion, use is generally madeof Lewis bases such as methylamine, aniline, dimethylamine,diethylamine, N-methylaniline, diphenylamine, N,N-dimethylaniline,trimethylamine, triethylamine, tri-n-butylamine, methyldiphenylamine,pyridine, p-bromo-N,N-dimethylaniline, p-nitro-N,N-dimethylaniline,triethylphosphine, triphenylphosphine, diphenylphosphine,tetrahydrothiophene and triphenylcarbenium.

Examples of such ionic compounds which have noncoordinating anions andcan be used for the purposes of the present invention are

triethylammonium tetra(phenyl)borate,

tributylammonium tetra(phenyl)borate,

trimethylammonium tetra(tolyl)borate,

tributylammonium tetra(tolyl)borate,

tributylammonium tetra(pentafluorophenyl)borate,

tributylammonium tetra(pentafluorophenyl)aluminate,

tripropylammonium tetra(dimethylphenyl)borate,

tributylammonium tetra(trifluoromethylphenyl)borate,

tributylammonium tetra(4-fluorophenyl)borate,

N,N-imethylanilinium tetra(phenyl)borate,

N,N-diethylanilinium tetra(phenyl)borate,

N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,

N,N-dimethylanilinium tetrakis(pentafluorophenyl)aluminate,

di(propyl)ammonium tetrakis (pentafluorophenyl)borate,

di(cyclohexyl)ammonium tetrakis(pentafluorophenyl)borate,

triphenylphosphonium tetrakis(phenyl)borate,

triethylphosphonium tetrakis(phenyl)borate,

diphenylphosphonium tetrakis(phenyl)borate,

tri(methylphenyl)phosphonium tetrakis(phenyl)borate,

tri(dimethylphenyl)phosphonium tetrakis(phenyl)borate,

triphenylcarbenium tetrakis(pentafluorophenyl)borate,

triphenylcarbenium tetrakis(pentafluorophenyl)aluminate,

triphenylcarbenium tetrakis(phenyl)aluminate,

ferrocenium tetrakis(pentafluorophenyl)borate and/or

ferrocenium tetrakis(pentafluorophenyl)aluminate.

Preference is given to triphenylcarbeniumtetrakis(pentafluorophenyl)borate and/or N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate.

It is also possible to use mixtures of at least one Lewis acid and atleast one ionic compound.

Further use for cocatalyst components are borane or carborane compoundssuch as

7,8-dicarbaundecaborane(13),

undecahydrido-7,8-dimethyl-7,8-dicarbaundecaborane,

dodecahydrido-1-phenyl-1,3-dicarbaundecaborane,

tri(butyl)ammonium decahydrido-8-thyl-7,9-dicarbaundecaborate,

4-carbanonaborane(14),

bis(tri(butyl)ammonium) nonaborate,

bis(tri(butyl)ammonium) undecaborate,

bis(tri(butyl)ammonium) dodecaborate,

bis(tri(butyl)ammonium) decachlorodecaborate,

tri(butyl)aamonium 1-carbadecaborate,

tri(butyl)ammonium 1-carbadodecaborate,

tri(butyl)ammonium 1-trimethylsilyl-1-carbadecaborate,

tri(butyl)ammonium bis(nonahydrido-1,3-dicarbanonaborato)cobaltate(III),

tri(butyl)ammoniumbis(undecahydrido-7,8-dicarbaundecaborato)ferrate(III)

The support component C) of the catalyst system used according to thepresent invention can be any organic or inorganic, inert solid, inparticular a porous support such as talc, inorganic oxides and finelydivided polymer powder (e.g. polyolefins).

Suitable inorganic oxides are those of elements of groups 2, 3, 4, 5,13, 14, 15 and 16 of the Periodic Table of the Elements. Examples ofoxides preferred as supports include silicon dioxide, aluminum oxide andalso mixed oxides of the two elements and corresponding oxide mixtures.Other inorganic oxides which can be used alone or in combination withthe last-named preferred oxidic supports are, for example, MgO, ZrO₂,TiO₂ or B₂O₃, to name only a few.

Organic support materials are, for example, finely divided polyolefinpowders (e.g. polyethylene, polypropylene or polystyrene).

The support materials used, in particular the inorganic oxides,generally have a specific surface area in the range from 10 to 1000m²/g, a pore volume in the range from 0.1 to 5 ml/g and a mean particlesize of from 1 to 500 mm. Preference is given to supports having aspecific surface area in the range from 50 to 500 m²/g, a pore volume inthe range from 0.5 to 3.5 ml/g and a mean particle size in the rangefrom 5 to 350 mm. Particular preference is given to supports having aspecific surface area in the range from 200 to 400 m²/g, a pore volumein the range from 0.8 to 3.0 ml/g and a mean particle size of from 10 to200 mm.

The preparation of the supported catalyst is generally not critical.Useful variants are the following:

In variant 1, in general at least one metallocene component A), usuallyin an organic solvent, is brought into contact with the cocatalystcomponent B) to give a dissolved or partly suspended product. Thisproduct is then generally added to the support material, which may havebeen pretreated as described above, preferably porous silicon dioxide(silica gel), the solvent is removed and the supported catalyst isobtained as a free-flowing solid. The supported catalyst can then beadditionally prepolymerized, for example using C₂-C₁₀-alk-l-enes.

In variant 2, the supported metallocene catalyst is generally obtainedby means of the following process steps

a) reaction of an inorganic support material, preferably porous silicondioxide as described above, with a passivating agent, as describedabove, preferably a tri-C₁-C₁₀-alkylaluminum such as trimethylaluminum,triethylaluminum or triisobutylaluminum,

b) reaction of the material obtained in this way with a metalloconecomplex A), preferably a metallocone complex of the formula I, in finemetal dihaldide form and a compound B) capable of forming metalloceniumions, and subsequent

c) reaction with an organometallic compound of an alkali metal, alkaliearth metal or element of main group III, preferably atri-C₁-C₁₀-alkylaluminum such as trimethylaluminum, triethylaluminum ortriisobutylaluminum.

This process is described in detail in DE-A 19 606 197, which is herebyexpressly incorporated by reference.

As additive, a small amount of an olefin, preferably a 1-olefin such as1-hexene or styrene, as activity-promoting component or an antistaticcan be added during or after the preparation of the supported catalystsystem. The molar ratio of additive to metallocene component (compoundI) is preferably from 1:1000 to 1000:1, very particularly preferablyfrom 1:20 to 20:1.

The supported catalyst system prepared according to the presentinvention can either be used directly for the polymerization of olefinsor can be prepolymerized using one or more olefinic monomers before itis used in a polymerization process. The method of carrying out theprepolymerization of supported catalyst systems is described in WO94/28034.

The polymers of the present invention can advantageously be convertedinto fibers, films and moldings.

The moldings, in particular the tubes, can be advantageously used in theconstruction of chemical apparatus, as drinking water pipes or aswastewater pipes.

Furthermore, the moldings comprising the propylene polymers of thepresent invention can be used for producing semifinished parts (examplesare rods, plates, fittings, profiles, e.g. via an injection-moldingprocess) or blow-molded containers or air conduits in the motor vehiclesector.

EXAMPLES

The following examples illustrate the invention. To characterize theproducts produced, the following polymer analysis methods were used:

30 Melt flow rate MFR (230/5) in accordance with ISO 1133

viscosity number [ml/g] determined at 135° C. in decalin

Creep rupture strength (CRS) in accordance with ISO 1167

Impact toughness of a tube in accordance with DIN 8078

n_(iso)=mean length of the isotactic sequences; determined by ¹³C-NMRspectroscopy (see Zambelli et al., Macromolecules 8, 687-689(1975))

Proportion of xylene-soluble material (in % by weight)

A polymer sample was completely dissolved in boiling xylene and themixture was allowed to cool to 20° C. The insoluble material wasfiltered off, dried to constant weight and weighed. The ratio of theweight of polymer obtained after drying to the weight of polymer used atthe beginning was calculated as a percentage.

Example A

Preparation of a supported catalyst system (catalyst 1)

22.2 g (3.55 mmol) ofrac-dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloridewere dissolved at room temperature in 177.5 ml (640 mmol of Al) of 30%strength methylaluminoxane solution in toluene. For preactivation, themixture was allowed to stand in the absence of light at 25° C. for 18hours. The metallocene-MAO solution prepared in this way wassubsequently diluted with 434.5 ml of toluene to a total volume of 612ml. 153 g of SiO₂ ¹) were slowly introduced into this solution. Theratio of the volume of solution to the total pore volume of thesupportmaterial was 2.5. After the addition was complete, the mixturewas stirred at room temperature for 5 minutes. The mixture wassubsequently evaporated to dryness at 40° C. under reduced pressure overa period of 2 hours and the residue was dried at 25° C. and 10⁻³ bar for5 hours. This gave 201 g of a free flowing pink powder which, accordingto elemental analysis, contained 0.14% by weight of Zr and 8.1% byweight of Al.

1) Silica grade MS 948, W. R. Grace, Davison Chemical Division,Baltimore, Md., USA, pore volume 1.6 ml/g, calcined at 800° C.

Example 1

A 70 liter reactor was, after carefully having been made inert, chargedwith 10 liters of liquid propylene at 30° C. 10 mmol oftriisobutylaluminum were added and the mixture was stirred at 30° C. for15 minutes. 5250 mg of catalyst 1 were subsequently added and, in afurther step, 2.21 standard 1 of H₂ were introduced.

The contents of the reactor were heated to 70° C. while stirring and thepolymerization commenced. The temperature was kept constant at 70° C.for one hour. The contents of the reactor were worked up by venting.

7.5 kg of PP were obtained, from which a catalyst yield of 1.4 kg ofPP/g of cat. can be calculated. An MFR (230/5) of 0.34 dg/min wasdetermined. The proportion of xylene-soluble material was determined as0.3% by weight. The proportion of acetone-soluble material wasdetermined as 0.05% by weight.

Comparative Example 1

The procedure of Example 1 was repeated, but 3.4 standard 1 of H₂ wereintroduced. 5250 mg of catalyst 1 were used. 8.5 kg of PP were obtained,from which a catalyst yield of 1.6 kg of PP/g of cat. could becalculated. An MFR (230/5) of 0.9 dg/min was determined on a sample.

Example 2

In a further experiment, the procedure of Example 1 was repeated, but apolymerization temperature of 50° C. was selected. 7670 mg of catalyst 1were subsequently added. No hydrogen was introduced.

2.4 kg of PP were obtained, from which a catalyst yield of 0.3 kg ofPP/g of cat. could be calculated. An MFR (230/5) of 0.16 dg/min wasdetermined on a sample. The viscosity number was 696 ml/g.

Example 3

In a further experiment, the procedure of Example 2 was repeated.

7670 mg of catalyst 1 and 23.1 standard 1 of H₂ were used. The additionsequence was as in Example 1.

5.3 kg of PP were obtained, from which a catalyst yield of 0.7 kg ofPP/g of cat. could be calculated. An MFR (230/5) of 35.3 dg/min wasdetermined on a sample. The viscosity number was 202 ml/g.

Example 4

In a further experiment, the procedure of Example 2 was repeated.

8400 mg of catalyst 1 were added. No hydrogen was initially introduced.

The polymerization time was extended to 90 minutes, after which 23.1standard 1 of H₂ were introduced. The polymerization was continued for afurther 18 minutes at the same temperature.

12 kg of PP were obtained, from which a catalyst yield of 1.7 kg of PP/gof cat. could be calculated. An MFR (230/5) of 0.86 dg/min wasdetermined on a sample. The viscosity number was 468 ml/g.

The melting point was 152.1° C.; the heat of fusion was 96.3 J/g.

The proportion of xylene-soluble material was determined as 0.3% byweight.

The proportion of acetone-soluble material was determined as 0.05% byweight.

The triad distribution (mm; mr; rr) was determined by NMR spectroscopy:

From these data, the isotactic sequence length niso was calculated as76.

Example 5

In a further experiment, the procedure of Example 4 was repeated.

3910 mg of catalyst 1 were added, no hydrogen was introduced initially.

The polymerization time was extended to 120 minutes, after which 29.9standard 1 of H₂ were introduced. The polymerization was continued for afurther 30 minutes at the same temperature.

12.9 kg of PP were obtained, from which a catalyst yield of 3.3 kg ofPP/g of cat. could be calculated. An MFR (230/5) of 1.9 dg/min wasdetermined on a sample. The viscosity number was 417 ml/g.

The proportion of xylene-soluble material was determined as 0.2% byweight.

The proportion of acetone-soluble material was determined as 0.05% byweight.

The melting point was 149.9° C.; the heat of fusion was 96.6 J/g.

Example 6

In a further experiment, the procedure of Example 5 was repeated.

2890 mg of catalyst 1 were added. 3.4 standard 1 of hydrogen wereintroduced initially.

The polymerization time was set to 60 minutes, after which 26 standard 1of H₂ were added. The polymerization was continued for a further 48minutes at the same temperature.

11.9 kg of PP were obtained, from which a catalyst yield of 4.1 kg PP/gof cat. could be calculated. An MFR (230/5) of 3.9 dg/min was determinedon a sample.

Example 7

50 liters of liquid propylene were placed in the reactor at 30° C. Forpreactivation, 10 mmol of triisobutylaluminum were added and the mixturewas stirred at 30° C. for 15 minutes. 5878 mg of catalyst 1 weresubsequently added and, in a further step, 0.2 standard 1 of H₂ wereintroduced.

The contents of the reactor were heated to 70° C. and the polymerizationstarted. After 10 minutes, the contents of the reactor were carefullydepressurized to a pressure of 25 bar. 3 standard 1 of hydrogen weresubsequently added. Polymerization was continued for 1 hour in the gasphase while stirring. The pressure was kept constant at 25 bar byaddition of propylene.

After one hour, 30 standard 1 of hydrogen were introduced, resulting ina presure rise to 27 bar.

Polymerization was continued for 1 hour in the gas phase while stirring.

The pressure was kept constant at 27 bar by addition of propylene.

12.4 kg of PP were obtained, from which a catalyst yield of 3.4 kg ofPP/g of cat. could be calculated. An MFR (230/5) of 3.9 dg/min wasdetermined on a sample.

Example 8

50 liters of liquid propylene were placed in the reactor at 30° C. Forpreactivation, 10 mmol of triisobutylaluminum were added and the mixturewas stirred at 30° C. for 15 minutes.

5878 mg of catalyst 1 were subsequently added and, in a further step,2.2 standard 1 of H₂ were introduced.

The contents of the reactor were heated to 70° C. and the polymerizationstarted. Polymerization was continued for 1 hour while stirring. Thetemperature was kept constant by means of jacket cooling.

After one hour, the contents of the reactor were carefully depressurizedto a pressure of 25 bar; 30.5 standard 1 of hydrogen were introduced,resulting in a pressure rise to 27 bar.

Polymerization was continued for 1 hour in the gas phase while stirring.

The pressure was kept constant at 27 bar by addition of propylene.

10.4 kg of PP were obtained, from which a catalyst yield of 2.8 kg ofPP/g of cat. could be calculated. An MFR (230/5) of 2.8 dg/min wasdetermined on a sample.

Example 9

Polymerization was carried out continuously in two stirred reactors,each having a capacity of 16 l, connected in series. Both reactors werecharged with 10 l of liquid propylene. As cocatalyst, use was made oftriisobutylaluminum in a concentration of 1 mmol/l. The hydrogenconcentration in the liquid phase was set to 50 ppm by volume.

In the first reactor, a mixture of propylene was polymerized at 50° C.in the presence of the abovementioned catalyst 1. A further catalyst,cocatalyst, propylene and hydrogen were continuously metered in. Thepolymerization was operated at a solids content of 224 g of PP per literof suspension. This corresponds to a phase ratio of 3.3 l of liquidpropylene per kg of PP. Further hydrogen was metered in so that aconcentration of 50 ppm by volume was established in the liquid phase.

The PP obtained in the first reactor was, together with the catalyst,transferred to the second reactor. In the second reactor, furtherhydrogen and propylene were metered in. The H₂ concentration in theliquid phase was 410 ppm by volume. The reaction temperature in thesecond reactor was likewise 50° C. The polymerization was operated at asolids content of 324 g of PP per liter of suspension. This correspondsto a phase ratio of 1.9 l of liquid propylene per kg of PP.

The reaction product was continuously transferred from the reactor 2 toa flash vessel operated at 70° C. and a pressure of 0.4 bar. The polymerwas taken periodically from the flash vessel.

A catalyst yield of 5 kg of PP/g of catalyst was obtained. A molar massdistribution M_(w)/M_(n) of 6.0, an MFR of 1.2 dg/min and a viscositynumber of 550 ml/g were measured. The proportion of xylene-solublematerial was measured as 0.5% by weight.

Example 10

Propylene was polymerized in a polymerization plant to give PP. Thecatalyst (1) and triisobutylaluminum were mixed with one another andcontinuously prepolymerized in liquid propylene in a prepolymerizationreactor. The mixture of catalyst, triisobutylaluminum, propylene andpolypropylene was metered into the first reactor. In addition, propylenewas fed from a reservoir to the first reactor. Hydrogen was dissolved inthe liquid propylene and then introduced into the reactor by means ofthis stream. A concentration of 60 ppm of hydrogen was set in the liquidpropylene. 17 t/h of propylene were fed to the first reactor. In thereactor, propylene was converted into PP in the presence of catalyst 1.The reaction mixture was taken continuously from the first reactor andmetered into the second reactor. In the second reactor, a further 7 t/hof propylene were introduced. A concentration of 420 ppm of hydrogen wasset in this propylene stream. After passing through the second reactor,the reaction mixture was worked up in a stirred vessel bydepressurization to 18 bar and the PP and the gaseous components wereseparated from one another. The gaseous propylene was condensed,distilled and subsequently returned to the reservoir. Per liter ofliquid propylene fed to the first reactor, 0.9 mmol of aluminum alkyland 80 mg of catalyst were metered in.

In the first reactor, a phase ratio of 3.3 l of liquid propylene per kgof PP was set; in the second reactor, a phase ratio of 1.9 l of liquidpropylene per kg of PP was set. The ratio of the quantities of heatremoved from the reactors was 1.4:1 (1st reactor/2nd reactor). The PPproduct obtained had a polydispersity M_(w)/M_(n) of 7.0 and an MFR(230/5) of 0.9 dg/min.

Example 11

The powder obtained from Example 4 was granulated at about 240° C. underinert gas using a twin-screw extruder having a screw diameter of 53 mm.During granulation, 0.15% of ®Irganox 1010 and 0.15% of ®Hostanox PAR 24were added as stabilizers. In addition, a color mixture was added. TheM_(w)/M_(n) was determined on the granulated material obtained, giving avalue of 6.0.

Comparative Example 2

The powder obtained from Comparative Example 1 was granulated at about240° C. under inert gas using a twin-screw extruder having a screwdiameter of 53 mm. During granulation, 0.15% of ®Irganox 1010 and 0.15%of ®Hostanox PAR 24 were added as stabilizers. In addition, a colormixture was added. The M_(w)/M_(n) was determined on the granulatedmaterial obtained, giving a value of 3.8.

The granulated material obtained in this way was processed on a tubeextrusion plant comprising a 60 mm grooved-barrel extruder and a vacuumspray tank to give tubes having dimensions of 32×4.5 mm (internaldiameter=32 mm, wall thickneess=4.5 mm). The melt throughput was 150kg/h and the melt temperature was set to 210° C. The tube surface wasvery rough.

Example 12

The powder obtained from Example 4 was granulated at about 240° C. underinert gas using a twin-screw extruder having a screw diameter of 53 mm.During granulation, 0.2% of ®Irganox 1010 and 0.2% of ®Hostanox PAR 24were added as stabilizers. The M_(w)/M_(n) was determined on thegranulated material obtained, giving a value of 6.0. The melt flow rateMFR 230/2.16 (in accordance with ISO 1133) was 0.25 dg/min.

Example 13

Tensile bars (test specimens type 1A in accordance with ISO 527, Part 1)for determining physical property values were produced from granulatedmaterial from Example 12 on an injection molding machine.

Furthermore, tubes having dimensions of 32×3 mm (internal diameter=32mm, wall thickness=3 mm) were produced from the granulated material fromExample 12 on a tube extrusion plant comprising a 60 mm grooved-barrelextruder and a vacuum spray tank. The melt throughput was 150 kg/h andthe melt temperature was set to 210° C.

The following material properties were determined:

Tensile test in accordance with ISO 527, Parts 1 and 2

Charpy impact toughness in accordance with ISO 179/1eU

Notched impact toughness in accordance with ISO 179/1eA

DSC by internal Targor method

Long-term pressure test in accordance with ISO 1167, requirements inaccordance with DIN 8078

Impact toughness on a tube in accordance with DIN 8078

The results from the tensile test, the toughness tests and the DSCdetermination were compared with values determined on a granulatedmaterial having a narrow molar mass distribution. The test specimenswere in both cases produced under conditions which met the requirementsof ISO DIN 1873, Part 2.

It was found that the physical property values for Example 13 comparedto Comparative Example 2 M_(w)/M_(n)=3.8 indicated a higher stiffness atthe same toughness. The crystallite melting point was from 10 to 15° C.lower than in the case of conventional PP grades, which broughtsignificant advantages in processing (lower energy uptake by themachines).

Tube:

It was found that processing proceeded very uniformly and the tubesurface was very smooth both inside and outside. The quality of the tubesurface was characterized by comparing it with tubes produced from agranulated material having a narrow molar mass distribution (cf.Comparative Example 2 M_(w)/M_(n)=3.8) on the same tube extrusion plantunder identical conditions.

The impact toughness of the tubes was good and corresponded to therequirements of DIN 8078, Subclause 3.5. The tubes were subjected tovarious long-term pressure tests in accordance with the requirements ofDIN 8078:

Minimum time Test Test before rupture Achieved time temperature pressure(Specified) before rupture 95 3.5 N/mm² 1000 h = 11155 h Test complete

The minimum times before rupture prescribed for PP-H in DIN 8078 (PPtubes) were exceeded substantially. The tubes have very good creeprupture behavior and a smooth surface. The impact toughnessspecification for PP-H in accordance with DIN 8078 was met by the tube.

Example 14

The powder obtained from Example 5 was granulated at about 240° C. underinert gas using a twin-screw extruder having a screw diameter of 53 mm.During granulation, 0.2% of ®Irganox 1010 and 0.2% of ®Hostanox PAR 24were added as stabilizers. The M_(w)/M_(n) was determined on thegranulated material obtained, giving a value of 5.9. The melt flow rateMFR 230/2.16 (in accordance with ISO 1133) was 0.49 g/min.

Example 15

Tensile bars (test specimens type 1A) for determining physical propertyvalues were produced from granulated material from Example 14 on aninjection molding machine.

Furthermore, tubes having dimensions of 32×3 mm (internal diameter=32mm, wall thickness=3 mm) were produced from the granulated material fromExample 14 on a tube extrusion plant comprising a 60 mm grooved-barrelextruder and a vacuum spray tank. The melt throughput was 150 kg/h andthe melt temperature was set to 210° C.

The following material properties were determined:

Long-term pressure test in accordance with ISO 1167, requirements inaccordance with DIN 8078

Impact toughness on the tube in accordance with DIN 8078

The test specimens were in both cases produced under conditionscorresponding to the requirements of ISO DIN 1873, Part 2.

Tube:

It was found that processing proceeded very uniformly and the tubesurface was very smooth both inside and outside. The quality of the tubesurface was characterized by comparing it with tubes produced from agranulated material having a narrow molar mass distribution (cf.Comparative Example 2 M_(w)/M_(n)=3.8) on the same tube extrusion plantunder identical conditions.

The impact toughness of the tubes was good and corresponded to therequirements of DIN 8078, Subclause 3.5. The tubes were subjected tovarious long-term pressure tests in accordance with the requirements ofDIN 8078:

Minimum time Test Test before rupture Achieved time temperature pressure(Specified) before rupture 95 3.5 N/mm² 1000 h = 11443 h Test complete

The minimum times before rupture prescribed for PP-H in DIN 8078 (PPtubes) were exceeded very substantially. The tubes had very good creeprupture behavior and a very smooth surface. The impact toughnessspecification for PP-H in accordance with DIN 8078 was met by the tube.

Example 16

The granulated material obtained from Example 4 was subjected to anaqueous extraction. For this purpose, 8 g of the granules were placed ina cleaned conical flask and 250 ml of odor- and taste-free water (e.g.mains water) were added. The sample was extracted for 4 hours on a waterbath heated to 70° C. while stirring by means of a magnetic stirrer. Theextraction solution was decanted into a clean conical-shoulder bottlewhich had been rinsed with mains water. After cooling to 25° C.,dilution series were prepared from the test water. On these, the odorthreshold value (OT) and the taste threshold value (TT) were determinedby a test panel in accordance with prEN 1420-1 (1994-08).

An odor threshold value (OT)=1 and a taste threshold value (TT)=1 weredetermined, i.e. the test water is odor- and taste-free compared to thecomparison water.

The extruded tube obtained from Example 12/13 (metallocene PP) wassubjected to an aqueous extraction by closing the tube and filling itwith odor- and taste-free water (e.g. mains water). The water remainedstatic in the tube for 72 hours at 23° C. and was then placed in a cleanconical-shoulder bottle which had been rinsed with mains water. Thecontact experiment was repeated three times, so that three samples ofmigration water were obtained On these, the odor threshold value (OT)and the taste threshold value (TT) were determined by a test panel inaccordance with prEN 1420-1 (1994-08).

An odor threshold value (OT)=1-2 and a taste threshold value (TT)=1-2were determined on the 1st extraction.

On the 2nd and 3rd extractions, an odor threshold value (OT)=1 and ataste threshold value (TT)=1 were determined, i.e. the test water wasodor- and taste-free compared to the comparison water.

Comparative Example 3

The granulated material prepared in Comparative Example 2 was subjectedto the same test as in Example 16 (paragraph 1). An odor threshold value(OT)=8 and a taste threshold value (TT)=4-8 were determined. Thus, thewater had a clearly perceptible odor and taste compared to thecomparison water.

The tube from Comparative Example 2 was subjected to an aqueousextraction as in Example 16. An odor threshold value (OT)=8 and a tastethreshold value (TT)=4-8 were determined on the first extraction.

On the 2nd and 3rd extraction, an odor threshold value (OT)=4-8 and ataste threshold value (TT)=4 were determined, i.e. all 3 extractions hada clearly perceptible odor and taste compared to the comparison water.

Example 17

The tube obtained in Example 12/13 was subjected to an assessment of theodor behavior when heated. The test was carried out in accordance withthe VDA guideline 270 (VDA=Verband der deutschen Automobilindustrie[Association of the German Automobile Industry]). For this purpose,pieces of tube having a material volume of 50 cm³ were placed in a cleanand odor-free 1 l glass vessel which was closed using an odor-neutralseal and lid. The specimen was subsequently stored for 2 hours at 80° C.in an oven. The test vessel was taken from the oven and then cooled to atest room temperature of 60° C. before the odor assessment was carriedout.

The following evaluation scale was employed:

Grade 1 not perceptible

Grade 2 perceptible, not bothersome

Grade 3 clearly perceptible, but not bothersome

Grade 4 bothersome

Grade 5 very bothersome

Grade 6 unbearable

(Intermediate half grades can also be awarded)

The pipe pieces tested were given the Grade 1. Thus, no odor wasperceptible.

Comparative Example 4

Pipe pieces from Comparative Example 3 were subjected to the odor testas in Example 16. The grade determined was 4-5.

Example 18

Production of extruded boards

The extruded board was produced from the thermoplastic moldingcomposition in a manner known per se by extrusion. For this purpose, thepolymer described in Example 12 was melted and homogenized at about170-250° C. in an extruder and extruded through a slit die to produce anextrudate having a width and a thickness corresponding to the board.Cooling and taking-off were carried out on a three-roll polishing unitand a subsequent roller track in the manner customary for polyolefins.The continuously produced sheet was then cut laterally and to length.

Slabs and boards having a thickness of 50 mm were produced.

The boards obtained in this way had the following properties.

Smooth glossy surface Tensile E modulus in accordance with ISO527/2=1490 MPa Charpy notched impact toughness at 23° C., ISO179/leA=9.8 kJ/m²

Production of a solid rod

Solid rods were used as semifinished parts for further machining. Thesolid rods were produced from the granulated material obtained inExample 12 by extrusion in a continuous process. The granulated materialwas melted in an extruder at 170-250° C. The melt was then initiallycooled intensively at the circumference in a calibrating tube andsubsequently cooled in a thermostated water bath until the solid rod hadbecome sufficiently rigid.

Solid rods having a diameter of 500 mm were produced.

The solid rods obtained in this way had the following properties:

Low residual stress Tensile E modulus in accordance with ISO 527/2=1520MPa (measured on test specimens cut out on a milling machine) Charpynotched impact toughness at 23° C., ISO 179/leA=9.6 kJ/m²

Production of a pressed slab

Pressed slabs having a thickness of 50 mm were produced from thegranulated material obtained from Example 2.

Owing to the lower melting point, the pressed slabs could be producedusing a shorter heating time. For example, in the case of a 50 mm thickpressed slab, the heating time was reduced from 240 minutes to 200minutes.

The pressed slabs obtained in this way had the following properties:

Low residual stress Tensile E modulus in accordance with ISO 527/2=1480MPa (measured on test specimens cut out on a milling machine) Charpynotched impact toughness at 23° C., ISO 179/leA=9.7 kJ/m²

Example 19

The procedure of Example 18 was repeated, but the granulated materialfrom Example 14 was used.

The extruded boards obtained had the following properties:

Smooth glossy surface Tensile E modulus in accordance with ISO527/2=1560 MPa Charpy notched impact toughness at 23° C., ISO179/leA=9.5 kJ/m²

The solid rods obtained had the following properties:

Low residual stress Smooth glossy surface Tensile E modulus inaccordance with ISO 527/2=1530 MPa Charpy notched impact toughness at23° C., ISO 179/leA=9.6 kJ/m²

The pressed slabs obtained had the following properties: Low residualstress smooth glossy surface Tensile E modulus in accordance with ISO527/2=1540 MPa Charpy notched impact toughness at 23° C., ISO179/leA=9.3 kJ/m^(2.)

What is claimed is:
 1. A propylene polymer containing from 0 to 2.5% byweight of C₂-C₁₀-olefin comonomers and having an M_(w) of from 350,000to 1,000,000 g/mol, and M_(w)/M_(n) of from 4 to 10, a proportion byweight of the polymer fraction having a viscosity number of from 500 to1400 ml/g of from 20 to 80% of the total polymer and a proportion byweight of a polymer fraction having a viscosity number of from 200 to400 ml/g of from 20 to 80% of the total polymer and a mean isotacticsequence length of from 50 to 100, obtained by polymerization of themonomers in the presence of a catalyst system comprising a metalloceneas transition metal component.
 2. A propylene homopolymer as claimed inclaim
 1. 3. A fiber, film or molding comprising a propylene polymer asclaimed in claim
 1. 4. A molding as claimed in claim 3 which is a tube,plate or semifinished part.
 5. A molding as claimed in claim 3 which isin form of a hollow body.
 6. A chemical apparatus comprising thepropylene polymer defined in claim
 1. 7. A drinking water pipecomprising the propylene polymer defined in claim
 1. 8. A wastewaterpipe comprising the propylene polymer defined in claim 1.